Look what David Attenborough's found! The world’s biggest dinosaur

The veteran naturalist’s inner Indiana Jones was fired up after a shepherd spotted the tip of a gigantic fossil bone sticking out of a rock in the Argentinian desert nearly three years ago – a discovery that is now believed to be the biggest animal ever to walk the Earth.

Attenborough and the Giant Dinosaur will air on BBC1 later this month and will tell the story of the discovery of this new species of Titanosaur that was unearthed.

Filmed over two years, the programme follows the twists and turns of this forensic investigation. Sir David witnesses the uncovering, cleaning and examination of the vast fossils for the first time. Using state of the art graphics, the film reveals what scientists think the internal structure of a dinosaur looked like and how it worked.

At the end of the programme, Sir David will also be on hand at the unveiling of a 37m long skeleton model built by a Canadian and Argentinian team of model makers which represents the newly-discovered animal.

Measuring 37m long - close to four London buses put end to end – and weighing 70 metric tons, it is some beast. For comparison ‘Dippy’ the Diplodocus at the Natural History Museum, London is a mere 26m long.

The first bone turned out to be a 2.4m long femur (thigh bone), the largest ever found (see picture).

By the end of the dig the team had uncovered more than 220 bones. As the programme reveals, the bones all belong to a new species of the giant plant-eating Titanosaur which is yet to be given its own scientific name.

It is 10% bigger than Argentinosaurus, the current record holder in terms of body mass or weight (though not quite as heavy as the sea-dwelling Blue Whale).

Its heart would have been the weight of three people and at nearly 2m in circumference it pushed up to 90 litres of blood round with one beat. The Titanosaur would have eaten a skip-full of food a day, using its huge gut to slowly digest its plant-based diet.

The dinosaurs were from the Cretaceous Period around 66 to 145 million years ago, a time when large dinosaurs dominated South America. The new-found Titanosaur roamed the earth around 101.6 million years ago.